Preparation of multi-grade lubricating oil



H. R. IRELAND ETAL FUJI/RE Liquid Recycle VISCOSITY INDEX OF 650 FDEWAXED OIL Single Po\ 7 55 so as vlscosnv 0F 650 F" oewaxeo OIL ssu AT210F.

/m/en/0rs Henry R //e/0/7d M/thae/ T 5/77/75/0' ag-Hm Affomey UnitedStates Patent Ofifice 3,142,634 Patented July 28, 1964- 3,142,634PREPARATEQN OF MULTl-GRADE LUBRECATING GIL Henry R. Ireland, WestDeptford Township, Gloucester County, and Michael T. Smilski, MantuaTownship, Gloucester County, N.J., assignors to Socony Mobil OilCompany, Inc., a corporation of New York Filed Dec. 14, 1961, Ser. No.159,339 Claims. (Cl. 208-95) This invention relates to a method forpreparing multigrade lubricating oils. More particularly, this inventionrelates to the method of preparing multi-grade lubricating oils byhydrocracking particular deasphalted petroleum residuums at relativelylow pressures.

Various methods are known to improve lubricating oils by hydrogentreatment at relatively low pressures. For instance, US. Patents2,554,282, 2,787,582, and 2,904,505 describe procedures which hydrotreatvarious petroleum lubricating oil fractions under mild reactionconditions but avoid any substantial hydrocracking of these fractions.The hydrotreating procedures, however, have not been employed to preparemulti-grade oils. On the other hand, however, the preparation ofmulti-grade' lubricating oils by the catalytic treatment with hydrogenof deasphalted petroleum residuums to obtain combined hydrogenation andring scission is described in US. 2,960,458. The disadvantage of thisprocedure relates to the fact that excessively high pressures rangingfrom 3600 to 4000 p.s.i.g. are necessarily employed. These highpressures are required to obtain a sufi'icient conversion of thepetroleum fraction and provide suitable life of the catalyst to make theprocess commercially feasible. The use of higher pressures not onlyincreases the cost of the production of multi-grade lubricating oils butrequires expensive high pressure equipment. It would be, therefore,desirable to use relatively low pressures in the catalytic hydrocrackingmethod of producing multi-grade lubricating oils in relatively highyields and at the same time avoid frequent regeneration or replacementwhich may be required of the catalyst utilized therein.

It is an object of this invention to provide a commercially attractiveprocedure for preparing multi-grade lubricating oils in relatively highyields by hydrocracking certain deasphalted petroleum fractions atrelatively low reaction pressures. It is a further object to provide aprocedure for preparing multi-grade lubricating oils utilizingrelatively low catalytic hydrocracking reaction pressures wherein thelife of the catalyst is not undesirably short. These and other objectswill become apparent to those skilled in the art by the consideration ofthe following disclosure and appended claims.

Accordingly, a process for producing a multi-grade lubricating oil hasbeen discovered wherein a charge stock of deasphalted residuum having aviscosity index in the range from about 60 to about 100 and a viscosityat 210 F. in the range from about 60 to about 250 S.S.U. is contactedwith a recycle hydrocracked hydrocarbon stock boiling in the range fromabout 400 F. to about 700 F. which can be obtained by hydrocracking saidcharge stock, in which the volumetric ratio of said recycle stock tosaid charge stock ranges from about 0.111 respectively, to about 10:1,respectively, or higher. The combination of the deasphalted residuum andrecycle stock is passed over a catalyst having hydrogenation andcracking properties in the presence of hydrogen at a temperature in therange from about 700 F. to about 870 F., at pressures in the range fromabout 800 to about 2400 p.s.i.g. and a liquid hourly space velocity fromabout 0.2 to about 2.0. This hydrocracking reaction requires a hydrogenconsumption of at least about 750 standard cubic feet (s.c.f.) perbarrel of charge stock. The product of the hydrocracking procedureboiling above about 600 F. can be dewaxed, if necessary, and distilledto provide components which directly, or upon blending with each other,meet the S.A.E. specifications for a multi-grade lubricating oil andhave a viscosity index of 115 or above.

The starting charge stock which is used in the process of this inventioncan be any residuum boiling in excess of 600 F. obtained by distillationof a petroleum crude which after deasphalting with known low boilingdeasphalting hydrocarbons such as propane provides a charge stock oilhaving a viscosity index in the range from about 60 to 100, preferablyin the range from about to and viscosity at 210 F. of about 70 to about200 S.S.U. These residuums can be obtained by distillation from variouspetroleum crudes such as Kuwait, North African, Mid-Continent, GulfCoastal, West Texas, Tia Juana, and the like. Using a charge stock whichhas a viscosity index below about 60 and a viscosity at 210 F. belowabout 60 will generally not provide acceptable yields of multi-gradeoils.

The reaction conditions necessary to produce multigrade lubricating oilsof this invention require temperatures in the range from about 700 F. toabout 870 F., preferably in the range from about 725 to about 850 F. Thepressures which are employed include those ranging from about 800 poundsper square inch to about 2400 pounds per square inch, the liquid hourlyspace velocity which can be used ranges from about 0.1 to about 2.0,preferably in the range from about 0.2 to about 1.0. Utilizing theconditions described above, will provide conversions of the startingcharge stock (i.e., 100-material boiling above 650 F., expressed asvolume percent of charge), in the range from about 30 to about 60 volumepercent and minimum yields of desirable lubricating oil fractions ofabout 30 volume percent, generally in range from about 40 to 60 volumepercent, based on the deasphalted charge stock.

In hydrocracking operations, utilization of pressures in the range usedfor hydrotreating operations significantly increase the catalyst agingrate wherein frequent regeneration of the catalyst is necessary or earlyreplacement of the catalyst is a requirement. YVhen frequentregeneration of the catalyst is required, the production of the desiredproducts is seriously curtailed while early replacement of the catalystis extremely costly. To avoid these problems, high pressures aredesirable in hydrocracking operations to obtain acceptable yields of thedesired product and to prevent accumulation of various poisons such asthe deposit of carbonaceous materials and the like on the catalyst andprevent a significant decrease of catalytic activity or permanentcatalyst damage. In a hydrotreating operation, the principal reaction ishydrogenation while generally avoiding any type of cracking reaction andthe production of substantial catalytic poisons. In using hydrotreatingpressures, the problem of catalyst aging is not as acute as in ahydrocracking operation and low pressures can be used and are desirable.

By the process of this invention, relatively low hydrocracking pressurescan be utilized for the production of multi-grade lubricating oils inhigh yields by combining a hydrocracked hydrocarbon fraction boiling inthe range from about 400 to about 700 F. with a deasphalted residuumcharge stock in the hydrocracking zone. This hydrocracked hydrocarbonfraction can be obtained from the hydrocracked product of this processor other processes and combined with the deasphalted residuum chargestock in a volumetric ratio of 0.1:1 to about 10:1 or higher, preferablyin the range from 1:1 to 5 :1. The use of the recycle hydrocrackedfraction, herein, significantly decreases the catalyst aging rate by afactor of at least 2 at pressures below about 2400 p.s.i.g. Utilizingthe recycle operation of this invention would provide hydrocrackingoperations to remain on stream approximately two times as long as thenonrecycle hydrocracking operation before regeneration is required.Thus, significantly extending life of the catalyst in a relatively lowpressure hydrocracking process provides a commercially feasible andeconomically attractive method for producing multi-grade oils.

The catalyst employed in the process of this invention can include anytype of catalyst having hydrogenation and cracking properties. Suchcatalyst are known in the art, for instance, these hydrocrackingcatalysts can include oxides and sulfides of any metal of Group VI lefthand column of the Periodic System or mixture thereof, such as chromium,sulfide, molybdenum sulfide, tungsten sulfide and the like; oxides andsulfides of Group VIII of the Periodic Table or mixtures thereof such asthe sufides of iron, cobalt, nickel, palladium, platinum, rhodium,osmium, iridum; mixtures of the above oxides and sulfides of the metalsof Group VI left hand column and Group VIII such as a mixture of nickelsulfide and tungsten sulfide; cobalt sulfide and molybdenum sulfide,nickel sulfide and molybdenum sulfide and the like. These metals can bedeposited on absorbent carriers such as alumina, silica-alumina,silica-zirconia, among others. Preferred catalysts include thosecomprising at least one of the metals having atomic numbers 44, 45, 46,76, 77 and 78 deposited on a composite-like oxide of at least 2 of themetals of Group IIA, IIB, IVA, and NB of the Periodic arrangement of theelements particularly Where such composite has an activity index inexcess of 25. Additional preferred catalysts include a sulfided orunsulfided 1 to 8 weight percent cobalt oxide and 3 to 20 Weight percentmolybdenum trioxide on a silicaalumina or silica-zirconia basecontaining silica in amounts from about 5 to about 95 Weight percent.

The preferable type of hydrogen which may be used herein is, of course,pure hydrogen. However, hydrogen of a low purity such as a recyclehydrogen from a reforming operation can be used. If recycle hydrogen isused, it is preferable to remove the various contaminants therefrom byconventional purification procedures. The hydrogen can be circulated inthis process at a ratio in the range from about 2000 to about 15,000standard cubic feet (s.c.f.) per barrel of deasphalted residuum charge.It is essential, however, in obtaining multi-grade lubricating oils thatthe hydrogen consumption exceed 750 s.c.f. per barrel of deasphaltedresiduum charge. Hydrogen consumption will depend on the type ofresiduum charged, reaction conditions used, the types of catalyst use,among other factors. In most instances, however, the hydrogenconsumption will generally range from about 900 to about 1500 s.c.f. perbarrel of deasphalted residuum charge.

The products from the hydrocracking operation are then distilled,preferably by vacuum distillation, to separate the desired lubricatingoil fractions from the low boiling reaction products such as, gases,gasoline, fuel oil and the like. These lubricating oils which boil aboveabout 600 F. may contain some wax products. Removal of wax, if present,can be accomplished by any treatment conventionally used for dewaxingoils to provide an oil having a pour point below about F. Lower pourpoints can be obtained, if desired. The lubricating oil obtained can beused without blending various components if the requirements ofmulti-grade oils are met. If it is desirable to meet variousspecifications, the dewaxed lubricating oils can be distilled andblended accordingly. A modification Which can be used relates to thedistillation of the hydrocracked lubricating oil into various oilcomponents followed by the dewaxing procedure and blending the resultingcomponents to obtain the desired multi-grade lubricating oil. Typical ofa satisfactory dewaxing process is the method wherein the oil isdissolved in a solvent, such as propane; methyl ethyl ketone andtoluene; and the like, cooling and filter- VISCOSITY VALUES OFMULTI-GRADE LUBRICATING OILS Viscosities, Saybolt Universal Seconds Oildesignation At 0 F. At 210 F.

Maximum Minimum Maximum 4. 000 45 less than 58 12, 000 45 less than 5812, 000 58 less than 70 12.000 70 less than 48. 000 58 less than 70 48,000 70 less than 85 The above-described multi-grade lubricating oils, ingeneral, require a viscosity index in excess of about 115.

The multi-grade lubricating oils produced by the process of thisinvention have a viscosity index in excess of about and can range ashigh as depending on the reaction conditions and initial charge stocksused. The advantage of the lubricating oils, produced herein, relates tothe fact that a viscosity index improver additive is generally notrequired; however, if higher viscosity indices are desired, minimumamounts of viscosity index improvers can be added. Additional oiladditives such as pour depressants, antioxidants, corrosion inhibitors,detergents, and the like can be added, if desired, to the multi-gradeoils obtained herein to provide further improvements and requirements.

The hydrocracking process of this invention can be carried out in anyequipment suitable for catalytic hydrocracking operations. The processmay be operated batchwise. It is preferable, however, and generally morefeasible to operate continuously. Accordingly, the process can beadapted to operations using a fixed bed of catalyst. Also, the processcan be operated using a moving bed of catalyst wherein the hydrocarbonflow can be concurrent or countercurrent to the catalyst flow. A fluidtype of operation may also be employed.

The following examples will serve to illustrate the process of theinvention without limiting the same:

Example 1 A Kuwait-Barco propane deasphalted raflinate was used as theresiduum charge stock to be hydrocracked. The charge stock had thefollowing properties.

The catalyst utilized in the hydrocracking operations was prepared inthe following manner:

A silica-zirconia support containing approximately 11 percent by weightZrO was prepared by reacting 320 cc. of aqueous zirconium sulfatesolution containing 0.05 g. ZrO /cc., 27 cc. of 50 percent by weightsulfuric acid, 1476 cc. of water and 700 cc. dilute N-Brand sodiumsilicate. The resulting silica-zirconia hydrosol set to a firm hydrogelin 30-50 seconds having a 6.3-6.8 pH. This gel was aged for 24 hours inwater at room temperature, and then for 48 hours at 200 F. in /2 percentaqueous sulfuric acid solution reducing the pH of the hydrogel to 2.6.The hydrogel was thereafter base-exchanged with a 2 weight percentaqueous ammonium chloride solution free of chloride ion, water washedand dried for 16 hours at 280 F. in air and then calcined for 13 hoursat 1000 F. in air. The silica-zirconia gel base so obtained wascharacterized by a pore volume of 0.54 cc./g.; an apparent density of0.63 g./cc.; a surface area of 597 mP/g. and a weight composition of0.01 percent Na, 0.01 percent 50;, 11.1 percent ZrO and remainder SiOHydrocracking catalyst was prepared by first vacuum spray impregnatingthe above silica-zirconia gel with 10 percent M as a water solution ofammonium molybdate [(NH4)3MO70244H20], drying at 220 for hours andcalcining 3 hours at 1000 F. in air. The resulting composite was thenimpregnated with 3 percent CoO as a water-solution of cobalt nitratedried at 230 F. for 3 hours and calcined 10 hours at 1000 F. in air. Theresulting catalyst was sulfided with a 50 percent H 50 percent H Smixture employing 2 volumes per volume of catalyst per minute for 5hours at 800 F.

Example 2 Using the deasphalted residuum charge stock and catalystdescribed in Example 1, a single pass and recycle hydrocrackingoperation are conducted over a 7 day period utilizing the followingconditions:

Operation Single Pass Recycle Recycle hydrocracked stock (400-700 F.),

volume per volume of fresh feed 0 1. 1 Pressure, ponds per square inchgauge- 2,000 2, 000 Temperature, F. (average) 770 728 Liquid hourlyspace velocity of charge stoc 0.5 0.5 Hydrogen circulation, standardcubic feet per barrel of charge stock 10, 000 10,000 Catalyst agingrate, F. per day appg tlg 5 to 0.1

Conversions (loo-products boiling above 650 F, expressed as volumepercent) 48-52 48-52 [Inspection of various fractions of hydrocrackedproduct boiling above 650 F. and dweaxed to a pour point of 20 The datadescribed in the above example is graphically illustrated in theaccompanying figure wherein the fractions having the same viscosity ofdewaxed oil boiling in excess of 650 F. obtained from a single passoperation and a recycle operation using similar reaction conditions isplotted versus the viscosity index of the oil. The accompanying figuredemonstrates the production of 'superior multi-grade oils of the recycleoperation over the single pass operation. The recycle operation not onlyprovides superior multi-grade lubricating oils but extends the life ofthe catalyst utilized by a factor of at least 5 over the single passoperation at the pressures utilized. The use of the recycle operationpermits longer on-time stream operation in the production of lubricatingoils and requires fewer regenerations than the single pass operationover the useful life of the catalyst. Similar improvements in using therecycle operation of this invention which are demonstrated in thisexample are also realized when pressures of about 2400 pounds per squareinch gauge are utilized.

To demonstrate the comparative data of extremely low pressures in thehydrocracking operations, of single pass versus recycle operations, thedeasphalted residuum and catalyst described in Example 1 are used underthe following conditions:

[Inspection of 50 8.8.110. 210 F. oil of hydrocracked pgoldalct boilingabove 650 and dewaxcd to a pour point of 20 Single Recycle passViscosity Index 114 123 118 Viscosity:

S.S.U. 0 F. (extrapolated) 12, 500 9,500 11, 500 S.S.U. F 231 205 216Meets requirements of a 10W/2O multi-grade oil no yes yes The data ofthe above example demonstrates again the significant improvement of thecatalyst aging rates of the recycle operation over the single passoperation. At a pressureof 1000 pounds per square inch gauge thecatalyst aging rate of the single pass operation is about 2 timesgreater than for the recycle operation. Furthermore, in the separationof an oil having a viscosity of 210 F. of 50 S.S.U., the productobtained by the single pass operation does not meet the S.A.E.requirements of a 10W/ 20 multi-grade oil. It should be noted, however,that in the recycle operation at pressures as low as 800 pounds persquare inch, the catalyst aging rate is slightly lower than the singlepass operation at higher pressures yet provides an oil which meets theS.A.E. specifications of a 10W/ 20 multi-grade lubricating oil.

In the above Examples 2 and 3, the recycle operation requires a hydrogenconsumption in excess of about 750 standard cubic feet (s.c.f.) ofhydrogen per barrel of charge stock to provide the multi-gradelubricating oils. The hydrocracked cycle stock boiling in the range fromabout 4 00 to about 700 P. which can be used in the recycle operation ofthis invention is obtainable from the same hydrocracking operation whichis preferable or from a completely different hydrocracking operationutilizing a petroleum charge stock.

It should be understood that this invention includes all changes andmodifications of the examples of the invention herein chosen forpurposes of disclosure Which do not constitute departures from thespirit and scope of the invention.

What is claimed is:

1. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 60 to about100 and a viscosity at 210 F. from about 60 to about 250 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of ahydrocracking catalyst at a temperature in the range from about 700 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity from about 0.2 to about 2.0and a hydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, and separating from the hydrocrackedproduct a multi-grade lubricating oil having a maximum and minimumviscosity limits of the S.A.E. specifications and a viscosity index inexcess of about 115.

2. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 60 to about100 and a viscosity at 210 F. from about 60 to about 250 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 1700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of ahydrocracking catalyst at a temperature in the range from about 700 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity from about 0.2 to about 2.0and a hydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charg stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F. and separatingcomponents of said dewaxed product to obtain a multi-grade lubricatingoil having a maximum and minimum viscosity limits of the S.A.E.specifications and a viscosity index in excess of about 115.

3. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltingresiduum charge stock having a viscosity index from about 60 to about100 and a viscosity at 210 F. from about 60 to about 250 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 1:1, respectively, to about5:1, respectively, with hydrogen in the presence of a hydrocrackingcatalyst at a temperature in the range from about 700 F. to about 870F., at pressures in the range from about 800 to about 2400 p.s.i.g., ata liquid hourly space velocity from about 0.2 to about 2.0 and ahydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F. and separatingcomponents of said dewaxed product to obtain a multi-grade lubricatingoil having a maximum and minimum viscosity limits of the S.A.E.specifications and a viscosity index in excess of about 115.

4. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 60 to about100 and a viscosity at 210 F. from about 60 to about 250 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of ahydrocracking catalyst at a temperature in the range from about 700 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity from about 0.2 to about 2.0and a hydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, dewaxing the hydrocrackecl productboiling above 600 F. to a pour point below about 20 F. and separatingfractions which upon blending have a maximum and minimum viscositylimits of the S.A.E. specifications and a viscosity index in excess ofabout 115.

5. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge having a viscosity index from about 75 to about and aviscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of ahydrocracking catalyst at a temperature in the range from about 7 00 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity from about 0.2 to about 2.0and a hydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F. and separatingcomponents of said dewaxed product to obtain a multi-grade lubricatingoil having a maximum and minimum viscosity limits of the S.A.E.specifications and a viscosity index in excess of about 115.

6. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 75 to about100 and a viscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 1:1, respectively, to about5:1, respectively, with hydrogen. in the presence of a hydrocrackingcatalyst at a temperature in the range from about 700 F. to about 870F., at pressures in the range from about 800 to about 2400 p.s.i.g., ata liquid hourly space velocity from about 0.2 to about 2.0 and ahydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F. and separatingcomponents of said dewaxed product to obtain a multi-grade lubricatingoil having a maximum and minimum viscosity limits of the S.A.E.specifications and a viscosity index in excess of about 115.

7. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 75 to about100 and a viscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of ahydrocracking catalyst at a temperature in the range from about 700 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity from about 0.2 to about 2.0and a hydrogen consumption in excess of about 750 s.c.f. per barrel ofdeasphalted residuum charge stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F., and separatingfractions which upon blending have a maximum and minimum viscositylimits of the S.A.E. specifications and a viscosity index in excess ofabout 115.

8. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 75 to about100 and a viscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of catalystwhich comprises a sulfided mixture of cobalt oxide and molybdenumtrioxide on a silica-Zirconia base at a temperature in the range fromabout 700 F. to about 870 F., at pressures in the range from about 800to about 2400 p.s.i.g., at a liquid hourly space velocity from about 0.2to about 2.0 and a hydrogen consumption in excess of about 750 s.c.f.per barrel of deasphalted residuum charge stock, dewaxing thehydrocracked product boiling above 600 F. to a pour point below about 20F. and separating components of said dewaxed product to obtain amulti-grade lubricating oil having a maximum and minimum viscositylimits of the S.A.E. specifications and a viscosity index in excess ofabout 115.

9. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about 75 to about100 and a viscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 1:1, respectively, to about5:1, respectively, with hydrogen in the presence of catalyst whichcomprises a sulfided mixture of cobalt oxide and molybdenum trioxide ona silica-zirconia base at a temperature in the range from about 700 F.to about 870 F., at pressures in the range from about 800 to about 2400p.s.i.g., at a liquid hourly space velocity 10 I from about 0.2 to about2.0 and a hydrogen consumption in excess of about 750 s.c.f. per barrelof deasphalted residuum charge stock, dewaxing the hydrocracked productboiling above 600 F. to a pour point below about 20 F. and separatingcomponents of said dewaxed product to obtain a multi-grade lubricatingoil having a maximum and minimum viscosity limits of the S.A.E.specifications and a viscosity index in excess of about 115.

10. A method for producing multi-grade lubricating oils by hydrocrackingat relatively low pressures which comprises contacting a deasphaltedresiduum charge stock having a viscosity index from about to about and aviscosity at 210 F. from about 70 to about 200 S.S.U. with ahydrocracked cycle hydrocarbon stock boiling in the range from about 400F. to about 700 F. in a volumetric ratio of said cycle stock to saiddeasphalted residuum charge stock from about 0.1:1, respectively, toabout 10:1, respectively, with hydrogen in the presence of catalystwhich comprises a sulfided mixture of cobalt oxide and molybdenumtrioxide on a silica-zirconia base at a temperature in the range fromabout 700 F. to about 870 F., at pressures in the range from about 800to about 2400 p.s.i.g., at a liquid hourly space velocity from about 0.2to about 2.0 and a hydrogen consumption in excess of about 750 s.c.f.per barrel of deasphalted residuum charge stock, dewaxing thehydrocracked product boiling above 600 F. to a pour point below about 20F., and separating fractions which upon blending have a maximum andminimum viscosity limits of the S.A.E. specifications and a viscosityindex in excess of about 115.

References Cited in the file of this patent UNITED STATES PATENTS1,951,792 Harding Mar. 20, 1934 2,904,505 Cole Sept. 15, 1959 2,960,458Beuther et a1. Nov. 15, 1960 2,967,146 Manley Jan. 3, 1961 3,011,974Henke et a1. Dec. 5, 1961 3,046,218 Henke et a1. July 24, 1962 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. a, 142,634July 28, 1964 Henry R. Ireland et a1.

, It is hereby certified that error appears in the above numbered patentfeqiiring correction and that the said Letters Patent should read ascorrected below. I

Column 3 line 50 for "use" read used column 5 llxample 2 first tableunder the heading "-=Operacion" third line thereof for "ponds" read-pounds same table -underthe heading "Recycle" first line thereoi for"l. 1" read 121 under same heading "Recycle", third line t..hereof,, afor ""728" read 782 column 7 line 30, for 1700 F0 read "(00 F. column 8line 16 after "charge" insert stock Signed and sealed this lst day ofDecember 1964. (SEAL) Attest:

ERNEST w s'wwER EDWARD J; BRENNER enlisting Officer Commissioner ofPatents

2. A METHOD FOR PRODUCING MULTI-GRADE LUBRICATING OILS BY HYDROCRACKING AT RELATIVELY LOW PRESSURES WHICH COMPRISES CONTACTING A DEASPHALTED RESIDUM CHARGE STOCK HAVING A VISCOSITY INDEX FROM ABOUT 60 TO ABOUT 100 AND A VISCOSITY AT 210*F. FROM ABOUT 60 TO ABOUT 250 S.S.U. WITH A HYDROCRACKED CYCLE HYDROCARBON STOCK BOILING IN THE RANGE FROM ABOUT 400*F. TO ABOUT 1700*F. IN A VOLUMETRIC RATIO OF SAID CYCLE STOCK TO SAID DEASPHALTED RESIDUUM CHARGE STOCK FROM ABOUT 0.1:1, RESPECTIVELY TO ABOUT 10:1, RESPECTIVELY, WITH HYDROGEN IN THE PRESENCE OF A HYDROCRACKING CATALYST AT A TEMPERATURE IN THE RANGE FROM ABOUT 700*F. TO ABOUT 870*F. AT PRESSURES IN THE RANGE FROM ABOUT 800 TO ABOUT 2400 P.S.I.G., AT A LIQUID HOURLY SPACE VELOCITY FROM ABOUT 0.2 TO ABOUT 2.0 AND A HYDROGEN CONSUMPTION IN EXCESS OF ABOUT 750 S.C.F. PER BARREL OF DEASPHALTED RESIDUUM CHARGE STOCK, DEWAXING THE HYDRCRACKED PRODUCT BOILING ABOVE 600*F. TO A POUR POINT BELOW ABOUT 20*F. AND SEPARATING COMPO- 